2006-04-04 04:00:00 PDT Washington -- Rep. Tom DeLay, R-Texas, a primary architect of the Republican majority who became one of the most powerful and feared leaders in Washington, told House allies Monday night he will give up his seat rather than face a re-election fight that appears increasingly unwinnable.

The decision came three days after his former deputy chief of staff, Tony C. Rudy, pleaded guilty to conspiracy and corruption charges, telling federal prosecutors of a criminal enterprise being run out of DeLay's leadership offices.

Rudy's plea agreement did not implicate DeLay in any illegal activities, but by placing the influence-buying efforts of disgraced Republican lobbyist Jack Abramoff directly in DeLay's operation, the former aide may have made an already difficult re-election bid all but out of reach.

DeLay, who will turn 59 on Saturday, did not say precisely when he would step down, but under Texas law, he must either die, be convicted of a felony or move out of his district to be removed from the November ballot. DeLay told Time magazine that he is likely to change his residence to Alexandria, Va., by the end of May. He said he informed President Bush of his decision Monday afternoon.

"This had become a referendum on me," he told Time in an article posted on the magazine's Web site. "So it's better for me to step aside and let it be a referendum on ideas, Republican values and what's important for this district."

Asked if he had done anything illegal or immoral in public office, DeLay replied: "No."

Former aides and sources close to Delay said his decision was not motivated by Rudy's guilty plea but by DeLay's concerns that he might lose his suburban Houston seat to his Democratic opponent, former Rep. Nick Lampson, and his belief that another Republican could win instead. DeLay's re-election race was expected to be one of the most expensive House campaigns in history and a drain on GOP coffers. Once DeLay steps aside, the Texas Republican Party will choose a replacement candidate.

Senior House Republicans have been saying for several weeks that DeLay would decide based on what was best for the GOP. Indeed, Democratic House campaign officials have been hoping to face DeLay in November, whom they believe could be the weakest Republican candidate they could hope for.

DeLay got a temporary political boost last month when he fended off three challengers to win a Republican primary with 62 percent of the vote. But recent polls showed an uphill climb against Lampson and another former congressman, Steve Stockman, who had cut his ties to the Republican Party to run as an independent. In early January, a Houston Chronicle poll showed DeLay trailing Lampson 30 percent to 22 percent, with Stockman taking 11 percent.

Richard Cullen, DeLay's lawyer, said Monday evening that his client's decision to withdraw was "not connected to the criminal investigation."

DeLay's decision capped a long, difficult slide from power that began in September, when a Texas grand jury indicted him on money-laundering and illegal campaign finance charges. Under House Republican rules, DeLay had no choice but to relinquish his post as majority leader, but he vowed to beat the charges and quickly return to power.

In the ensuing months, the separate federal corruption probe stemming from Abramoff's activities drew closer to DeLay, first eliciting a guilty plea from DeLay's former press secretary, Michael Scanlon, then from Abramoff, whom DeLay once described as "one of my closest and dearest friends." Some House Republicans publicly stated DeLay could not be allowed to return to the House leadership if his implication in the Abramoff scandal appeared inevitable.

In January, DeLay bowed to pressure from fellow Republicans and abandoned his quest to regain the majority leader's post. At that time, however, he pledged to seek re-election, and he quickly snared a coveted seat on the House Appropriations Committee.

His renunciation of the leader's post touched off a scramble among Republicans eager to move past the DeLay era. A month later, Rep. John Boehner, R-Ohio, upset DeLay's protege, House Majority Whip Roy Blunt, R-Mo., to win the highest position in the Republican conference, effectively ending the DeLay era of leadership that stretched back to Dec. 6, 1994, and the Republican Revolution.

When Republicans swept to power that year, DeLay capitalized on his fundraising prowess in a successful race for majority whip against Rep. Robert Walker, R-Pa. A former pest exterminator, DeLay had already been in Congress since 1985, and his fundraising largesse, especially with the huge freshman class of 1994, helped him overtake Walker, who was former Rep. Newt Gingrich's best friend.